1. Field of the Invention
For an electric extension cord, a terminal having safety guards to protect against electrical shock and burn.
2. Description of the Prior Art
It long has been recognized that electrical outlets represent a source of danger for electrical shocks and burns. This hazard is more likely for young children who fail to appreciate the danger of inserting objects into the prong-admitting passageways that lead to the female contacts housed in electrical outlets. Small children due to inherent curiosity and imitative behavior insert metallic objects into these prong-admitting passageways and as a result are shocked or burned, sometimes seriously and occasionally fatally.
Many attempts have been made to make electrical receptacles safer by providing closure mechanisms that block the contact sockets when a plug is not engaged therein. One approach has been to provide a pseudo-twin prong plug for an electrical wall outlet, the same being totally composed of electrically nonconductive material; the bases of the prongs are connected by a bridge molded in one piece with the prongs. This device, although in wide use, does not totally remove the danger since children may manage to work out the bridge and prongs.
Another approach to the problem involves the use of a special wall outlet which replaces a standard wall outlet. The special wall outlet includes a disc rotatably mounted over a wall outlet casing and including a pair of passageways that normally are disaligned with the passageways of the wall outlet casing but which can, by revolving the disc, be brought into alignment with the casing passageways. The disc is spring-biased into its out-of-alignment position so that to successfully couple a twin-prong plug to the wall outlet, the tips of the prongs are inserted into the passageways of the disc, the disc rotated through an arc, usually 90.degree., with the aid of the plug, and the prongs then thrust home into the passageways of the casing until they engage the female contacts. This second approach requires more coordination and dexterity than is possessed by most children and, therefore, is quite effective. However, the structure of the special wall outlet is rather expensive so that the same has not proven to be highly salable.
There is also on the market--and this is not an item which has any connection with safeguarding a child against the danger of electrical shock or burns--a molded-on terminal for an electric extension cord. The molded-on terminal has largely replaced the now-antiquated hollow cube tap which had comprised a pair of mating shells containing within them female contacts that were secured to the twin leads of the extension cord. In the molded-on connectors access to the female contacts was provided by prong-admitting openings. The previous terminals employed rigid shells, for example, shells molded of a phenolformaldehyde condensation resin, e.g., Bakelite. However, the molded-on terminals are made of an elastomeric plastic, e.g., a polyvinylchloride, which is a semi-soft, semi-rigid material typically having a Shaw durometer in the vicinity of 40, the same being exemplificative.
The elasticity of such a terminal is employed in U.S. Pat. No. 3,810,070 to provide a biasing force that urges an external, slidable safety guard to blocking position. The patent discloses a system in which the prong-admitting passageways of the safety guard are normally disaligned with the prong-admitting passageways of the elastomeric connector. However, the guard which is mounted for sliding movement over a face of the connector can be forced into a position in which it distorts the connector and its prong-admitting passageways are aligned with the prong-admitting passageways of the connector.